Pneumatic-despatch-tube apparatus.



A. 'w. PEARSALL.

PNEUMATIC DESPATCH TUBE APPARATUS.

APPLICATION FIL'ED SEPT. 16. 1912.

Patented Dec. 12, 1916.

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A. W. PEARSALL.

PNEUMATIC DESPATCH' TUBE APPARATUS. APPLICATION FILED SEPT- 16. 9 12,

Patented Dec. 12, 1916.

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PNEUMATIC DESPATCH TUBEAPPARATUS.

APPLICATION FILED SEPT-16, 19I2- Patented Dec. 12, 1916.

3 SHEETS-SHEET 3- mug- WASHINGT'JN. nv c ALBERT W. PEARSALL, OF LOWELL, MASSACHUSETTS, ASSIGNOR. TO THE LAIVISON COMPANY, (FORIVIEBLY LAMSON CONSOLIDATED STORE SERVICE COMPANY) OF BOSTON, MASSACHUSETTS, A CORPORATION" OF NEW JERSEY.

PNEUMATIC-DESPATCH-TUBE APPARATUS.

Specification of Letters Patent.

Patented Dec. 12, 1916.

To all whom it may concern.

Be it known that I, ALBEnT W. PEARSALL, of Lowell, in the county of Middlesex and State of Massachusetts, have invented cer tain new and useful Improvements in Pneulnatic-Despatch-Tube Apparatus, of which the following is a specification.

This invention relates to improvements in pneumatic despatch tube apparatus, and particularly to those systems which comprise a single transmission tube through which a carrier can be despatched in either direction.

The object of this invention isto pneumatically control the power from either terminal of said tube in such a manner as to cause the blower or pump which is connected with one end of the tube to supply a current of air in the proper direction for the transmission of the carrier. This 1s accomplished by means of a pneumatically operated switch controlled from either end of the transmission tube and adapted to reverse the direction of rotation of the motor and therefore of the blower or pump and necessarily changing the direction of the current of air in the transmission tube.

Another object of this invention is to automatically regulate and limit the operation of the blower or pump to the interval necessary to the proper transmission and delivery of the carriers.

Other important features of this invention will be hereinafter described and particularly pointed out in the claims.

1n the accompanying drawings whlch illustrate a construction embodying my in vention, Figure 1 is a diagrammatic view of the device in operating connection with a single tube pneumatic despatch system. Fig. 2 is an enlarged front elevation of the automatic motor reversing switch hereinafter described. Fig. 3 is an inverted plan view of the switch shown in Fig. 2. Fig. 41 is an enlarged view of the automatic tlming mechanism. Figs. 5 and 6 are enlarged details hereinafter described.

Like letters of reference refer to like parts throughout the several views.

A and B represent two stations connected by a transmisison tube C normally open to the atmosphere at station A and closed at the opposite end at station E by a lock valve 0 An elbow c connects the end of the transmission tube at station B with the blower or pump I by means of the tube 0 The blower 1 is driven by means of the belt 2 by electric motor 3; this motor 3 is serieswound and its circuit includes a normally open reversing switch 4- by means of which the motor may be started in either direction and stopped.

D is an ordinary cut out switch connecting the motor circuit with line wires L and L 'As shown in Figs. 2 and 3, the switch 4: comprises a plate or slate 5 to which is fixed a casing 6 containing a diaphragm 7 which normally maintains an intermediate position. To this diaphragm 7 is fixed a stem 8 movable vertically through the casing 6; at its upper end, the stem 8 is provided with a collar 9 adapted to cooperate with a yoke 10 pivoted at 10 to an extension 6 of the casing (5, and at its lower end said stem is con nected by a pin 11 with the slotted arms of two bell-crank levers 12, 13 pivotally mounted at 11 and 15 upon the slate 5. The longer arms of the bell cranks 12 and 13 carry, respectively, contacts 16 and 17, and are offset relatively, as shown in Fig. 3, so that when the stem 8 is lifted, said arms can pass each other as indicated by dotted lines Fig. 2. Mounted on the slate 5 in position to cooperate with the contacts 16 and 1.7 are two stationary contacts 18 and 19 against which one or the other of the contacts 16 and 17 is brought when the stem 8 is raised or lowered, that is, the stem 8 is held by the diaphragm 7 normally in an intermediate position whereby to position each of the parts 12 and 13 substantially in its median or inoperative position, in which these parts are shown in Fig. 2, and when said stem is raised, the bell cranks 12 and 13 are swung past each other into the dotted line positions shown in Fig. 2, thus connecting the bell crank 12 with the contact 19 and bell crank 13 with the contact 18, and when said stem is lowered, bell cranks 12 and 13 swing apart, thus connecting the bell crank 12 with the contact 18 and the bell crank 13 with the contact 19. To counterbalance the horizontal slotted short arm of the bell cranks, the latter are weighted as at 20 and 21.

Connected with the casing 6 at a point above the diaphragm 7 is a pipe 22 which extends to the station A and is provided at that end with a compressible bulb 23, and as will be clear, when this bulb is compressed by the operator at station A, air is forced into the casing 6 above the diaphragm 7 and the latter, together with the stem 8 is forced down into the lower dotted position .(Fig. 2) so that the bell .cranks 12 and 13 connect with the contacts 18 and 19 respectively. This results in the motor I being started in a direction to produce a current of air from station A to station B so that if a carrier be then inserted at stacarrier while traveling from station A to station B to hold the contacts 16 and 17 against contacts 18 and 19; to this end, a pipe 24 is provided which connects the easing 6 at a point below the diaphragm 7 With the tube .0 at a point just above the valve 0 so that after the carrier is inserted in the tube C at station A, and until it is discharged at station B, the relatively low pressure or vacuum in the tube C in front of the carrier acts through the pipe 24 to exhaust air from the lower part of easing 6 thereby holding the diaphragm 7 down until the carrier discharges at station B through the valve 0 which is accomplished by the carrier tripping the latch c and releasing the valve 0 As soon as the carrier passes the junction of pipe 24: and tube C, the pressure in the lower part of the casing 6 is restored to normal and the diaphragm 7 returns to its normal intermediate position, disconnecting the contacts 16 and 17, and 18 and 19, thereby stopping the motor I.

In sending a carrier from station B to station A, the operator at station B opens the valve 0 and inserts the carrier into the started in the opposite direction, that is, so

as to establish a current of air and propel the carrier from station B to station A.

In sending a carrier from station B to station A, it is not desirable to depend upon the operator at B holding the stem 8 elevated until the carrier despatched at B is delivered at A, and for this reason, the relatively high pressure in the tube C ber hind the carrier is utilized for this purpose.

stem 8 elevated until the carrier is delivered at station A. lVhen this happens, the high pressure below the diaphragm 7 is automatically relieved as hereinafter described, and the diaphragm 7 assumes its normal intermediate position breaking the circuit of motor I at 1617, and 1819. Mounted in the pipe 24: is a three-way valve 25 of which one of its ports 26 opens to the atmosphere; normally this valve 25 occupies the position shown in Fig. 5 with the port 26 closed and chamber 25 in communication with the tube C through the pipe 2 1-. \Vhen, however, av carrier traveling from station B to station A discharges at station A, the valve 25 is automatically shifted by means of timing mechanism into the position indicated by dotted lines in Fig. 5, thereby closing that section of pipe 24 leading to the tube C and opening to the atmosphere that section of pipe 241- which leads to casing 6. This results in the stopping of the motor I after .the carrier has delivered at station A.

In order to operate valve 25 automatically and at the proper time, there is provided a timing device comprising the cylinder 27 connected at its lower end by a port 28 with the tube C. At its upper end the cylinder 27 carries a relatively large port 29 controlled by an outwardly closing check valve 30, Fig. 6. Through the valve 30 extends a restricted by-pass 31 whose capacity is regulated by a screw valve 32; within the cylinder 27 is a piston 33 whose stem 84 is made at its upper end with a slot 35 into which extends an arm 36 fast to the stem 37 of the valve 25. Normally the piston 33 rests at the bottom of the cylinder 27, but when the motor I is started to propel a carrier from station B to station A, the pressure below the piston raises the latter against the resistance ofiered by the restricted by-pass 31 which is so regulated that when a. carrier discharges at station A and motor I should be stopped as described, the lower end of slot 35 engages the arm 36 and valve 25 is shifted from its full line position to its dotted line position, Fig. 5, which, as already described, results in stopping the motor I. As soon as the motor I stops, the pressure below the piston 33 falls and the weight of the latter causes it i to descend, the check valve 30 opening to permit the free entrance of air,'as the piston moves downward. The port 29 however, is of such capacity that the motor I is stopped before the upper end of slot 35 engages the arm 36 and restores the valve 25 to its normal position. IVhen closed by the operator at station A, the stem 8 then being forced down by means of bulb 23, the circuit of motor I is as follows: from line wire L llO lSt

through a wire 38 to hell crank 12 and con tact 16, thence to contact 18, from which a wire 38 leads to one brush of motor I; through armature of motor I to the other brush which is connected by Wire 40 with contact 19, thence through contact 17 and bell crank 13 to a wire 11 to the field of motor I; through field of motor I to wire 4:2 which connects with the other line L When closed by the operator at station 13, the stem S being then forced up, the circuit of motor I is as follows: from line Wire L, through wire 38 to bell crank 12 and contact 16 thence through contact 19 and wire 10 to one of the brushes of armature of motor I, through the armature to the other brush thence through wire 39 to contact 18, thence through contact 17, bell crank 18 and wire 41 to the field of motor I and through the field to wire 42 which connects with line wire L It will thus be seen that when stem 8 is raised from normal position, the current through the armature of motor I is in one direction, and when said stem 8 is depressed, the current through the armature is in the opposite direction, while the direction of the current through the field is always the same; thus when the stem 8 is raised by the operator at station E, the motor I will operate in one direction, and when said stem 8 is lowered by the operator at station A, the motor I will operate in the opposite direction.

I do not limit myself to the arrangement and construction shown, as it may be varied without departing from the spirit of my invention.

Having thus described the nature of my invention and set forth a construction e'mbodying the same, what I claim as new and desire to secure by Letters Patent of the' United States is:

1. In a pneumatic despatch tube apparatus, a transit tube for the transmission of carriers in either direction, a pump connected with said tubeand adapted to supply a current of air in either direction through said tube for the transmission of carriers, a motor adapted to drive said pump, a switching device for starting, stopping or reversing said motor, and pneumatically controlled means, subject in part at least to the pres sure in a portion of said tube, for operating said switching device to stop said motor.

2. In a pneumatic despatch tube apparatus, a transit tube for the transmission of carriers in either direction, a pump connected with said tube and adapted to be reversed for supplying a current of air in either direction through said tube for the transmission of carriers, a motor adapted to drive said pump, a switching device having a part thereof movable in either of two directions away from a median position, said device being adapted to start, stop or reverse said motor, and time element means for controlling a motor stopping operation of said switching device, said device having a tendency for its median position.

3. In pneumatic despatch apparatus, a tube, means for establishing a carrier-transmitting flow of air through said tube in either direction, and mechanism for controlling the duration of running of said means, when the latter is in operation, by either vacuum or plenum in a part of said tube, according to the direction of said flow.

1. In a pneumatic despatch tube apparatus, a transit tube for the transmission of carriers in either direction, a pump connected with said tube and adapted to be reversed for supplying a current of air in either direction through said tube for the transmission of carriers, a motor adapted to drive said pump, a switch adapted to start, stop or reverse said motor, means for timing the operation of said motor in one direction, and pressure controlled means adapted to co-act with said switch to stop the actuation of said motor when the latter is running in the opposite direction.

5. In a pneumatic despatch tube apparatus, a transit tube for the transmission of carriers in either direction, a pump connected with said tube and adapted to be reversed for supplying a current of air in either direction through said tube for the transmission of carriers, a motor adapted to drive said pump, a switch adapted to start, stop or reverse said motor, means for controlling the operation of said switch for starting or reversing said motor and for automatically stopping said motor when it is being driven in one direction, upon the establishment of a determined carrier transmitting condition in a part of the system, and means for timing the duration of opera tion of said motor when being driven in the opposite direction.

6. In pneumatic despatch apparatus, a transmission tube, means for establishing a carrier propelling current of air through said tube, and means for limiting the duration of said current to a determined period of time, said last mentioned means including a conduit in communication with said tube, a normally open valve in said conduit, means, subject to the pressure in said conduit, for controlling said first mentioned means, and time element mechanism for controlling said valve whereby to vary said pressure in said conduit.

7. In pneumatic despatch apparatus, a transmission tube, means for establishing a carrier propelling current of air through said tube, and means for limiting the duration of said current to a determined period of time, said last mentioned means including a conduit in communication with said tube, a valve in said conduit and adapted to obstruct the same when in its closed position,

: '8.'In pneumatic despatch, apparatus, a jtr'ansml'ssion tube, means including a reversible motor forestablishing a carrierpropolling current of air through said tube in either direction, and pneumatic timing means for automatically limiting the duration of said current to a substantially determined period of time when said motor is driven in one direction, said timing means being-substantially inoperative when said motor is being driven in the opposite direc 'tion, and means for stopping said motor when itis being driven in said opposite direction, after the transmission of a carrier by saldcurrent throughsaid tube to a determlned point.

9. In pneumatic despatch apparatus, a transmission tube, means, including a re 'Versible motor for establishing a carrier propelling current of air through said tube in either direction,-and timing means for automatically limiting the duration of said current to a substantially determined period of time when said motor is driven in one direction, said timing means being substantially inoperative when said motor is being driven in the opposite direction, and means for stopping said motor when it is being driven in said opposite direction, after the trans missionof 'a'carrler by sald current through i 'said' tube to a determined point.

[10. In pneumatic despatch apparatus, op-

erating mechanism for said apparatus, in

closed-in a casing, a transmission tube adapted for the transmisslon of earners in either direction therethrough, said tube extending from said casing, said mechanism including blower or pump, a reversible motor for 7 driving'the latter, a switching device for said motor, normally in a motor stopping position and means for actuatmg said device to drive said motor 1n one direction,

7 said means being operable from a point adjacent said casing, means to actuate said device for driving said motor in an opposite 1 direction,. operable from a point at sub- Q stantially the other end ofsaid tube, and

fOonies of this patent may be obtained for.

means to co-act with one of said switching device actuating means to return the latter to its motor stopping position independently of the travel of the carriers.

11. In a pneumatic despatch apparatus, a transmission tube, means, including a motor, reversible for establishing a current of air in said tube in either direction, a switching device for controlling said motor, and means adapted to be held in one of two positions to maintain parts of said switching device in operative relationship, by the pressure of the air flowing through said tube and in accordance with the direction of flow of said air.

12. In a pneumatic despatch apparatus, a transmission tube, means, including a motor, reversible for establishing a current of air in said tube in either direction, a switching device for controlling said motor, and means to maintain parts of said switching device in operative relationship, by the pressure of the air flowing through said tube and in accordance with the direction of flow of said air.

13. In a pneumatic despatch apparatus a transit tube for the transmission of carriers in either direction, a blower or pump connected with said tube and adapted to be .re-

-' versed for supplying a current of air in either direction through said tube for the transmission of carriers, a motor adapted ,to drive said blower or pump, a switch adapted to start, stop or reverse said motor, meansfor controlling the operation of said switch for starting or reversing said motor and for automatically stopping said motor when it is being driven in one direction, upon the establishment of a determined pressure in a part of the system, and means, co-acting with certain of the elements aforesaid, for controlling the duration of operation of said motor when being driven in an opposite direction.

In testimony whereof, I have signed my name to this specification in the presence of two subscribing witnesses.

ALBERT W. PEARSALL.

Witnesses:

M. G. MACMILLAN, ISAAC KRAFSUR.

five cents each, by addressing the Commissioner of Patents, Washington, D. 0. 

